Elevator for a reactor well and equipment storage area

ABSTRACT

An elevator for a reactor well and an equipment storage area wherein a service platform is raised and lowered within the reactor well and adjoining area for performing operations within the reactor well and the equipment storage area. Toward this end, stationary tubes are suspended in fixed relation from an overhead support. Telescopically received by the stationary tubes are movable, upright tubes. Fixed to the lower ends of the movable tubes for rectilinear movement therewith is the service platform. A lifting and lowering device, such as a cable and drum arrangement or a hydraulically actuated system, is mounted on the overhead support. The cables extend into the stationary tubes and are attached at their free ends to the movable tubes for raising and lowering the same, thereby raising and lowering the service platform. The movable tubes are spaced apart a distance slightly greater than the diameter of a reactor pressure vessel in the reactor well and a space is provided between the service platform and the adjacent superstructure of the refueling platform for the passage of equipment therebetween.

United States Patent 1 Jones 1 1 3,744,593 1451 July 10,1973

1 1 ELEVATOR FOR A REACTOR WELL AND EQUIPMENT STORAGE AREA [75]Inventor: Cecil R. Jones, San Jose, Calif.

[73] Assignee: Transfer Systems Incorporated, New

York, NY.

22 Filed: Apr. 13, 1971 21 1 Appl. No.: 133,687

52 US. Cl ..l87/17,182/37,I82/l44 51 Int. Cl ..B66b1l/04 [58] FieldoiSearch .,187/l7, 20-23,

Primary ExaminerEvon C. Blunk Assistant ExaminerMerle F. MaffeiAttorney-Jack Oisher 57] ABSTRACT An elevator for a reactor well and anequipment storage area wherein a service platform is raised and loweredwithin the reactor well and adjoining area for performing operationswithin the reactor well and the equipment storage area. Toward this end,stationary tubes are suspended in fixed relation from an overheadsupport. Telescopically received by the stationary tubes are movable,upright tubes. Fixed to thelower ends of the movable tubes forrectilinear movement therewith is the service platform. A lifting andlowering device, such as a cable and drum arrangement or a hydraulicallyactuated system, is mounted on the overhead support. The cables extendinto the stationary tubes and are attached at their free ends to themovable tubes for raising and lowering the same, thereby raising andlowering the service platform. The movable tubes are spaced apart adistance slightly greater than the diameter of a reactor pressure vesselin the reactor well and a space is provided between the service platformand the adjacent superstructure of the refueling platform for thepassage of equipment therebetween.

9 Claims, 7 Drawing Figures PAIENIEB H 3.744.593 V arm 1 or s A T TORNEY PATENTED JUL Y ("973 3. 744.593

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ATTORNEY l I l II PH H T m v 4 f m o a 2 a 3 3 mo m o A u. YAL C. n m0 A5 n 7 M 1\ w J\ 5 G n u i H 6 .1 H F I V I I 3 1 w 2 I k V Eula, Jr...7F o H a m a M w c m sp Z Ma ELEVATOR FOR A REACTOR WELL AND EQUIPMENTSTORAGE AREA BACKGROUND OF THE INVENTION The present invention relatesin general to a refueling platform and more particularly to an elevatorfor access to a reactor well. y

In refueling a light water moderated reactor access is required to thereactor well. After the reactor is shutdown and cooled, a shield blockis removed. Then the drywell head bolts are removed and the drywell headis stored on the refueling floor should the system be one that employspressure suppression. Reactor vessel head bolts are removed andconnections to the reactor pressure vessel head are operating Then, thereactor pressure head is stored on an oPerating floor. These steps takeseveral days, and different tools to complete. Heretofore, a ladder wasemployed to gain access to the reactor well. This arrangement was bothhazardous and time consuming.

Some installations have required the removal of a steam separator withthe associated hold down bolts to gain access over the reactor core. Inother systems, the equipment located above the core is removed. Water ispumped into the reactor well until the height thereof is above thereactor fuel and core, which provides adequate shielding for access.Equipment above the core, such as the steam dryer, is then removed byconventional sling equipment. A seal protector is installed in thereactor well and a portion of a rotating platform is lowered into thereactor well to remove the bolts from the steam separator. The portionof the rotating platform so lowered is accomplished by a sling whichrequired considerable time to perform and requires a ladder to gainaccess to auxiliary equipment for the removal of additional internalparts. While in some systems, a portion of the access platform solowered employed supporting telescoping tubes, the telescoping tubeswere mounted internally of the refueling platform, and, hence, made itimpractical to use auxiliary tools for performing the aforementionedoperations. Thus, the arrangement was inefficient as far as performingthe above-required operations and gaining access to additional internalparts in the reactor well. Some installations employed a circular trackmounted on a flange of the reactor pressure vessel and a platformtravelling in an annular path along the tracks. The installation andremoval of the circular track arrange ment was also time consuming and,therefore, inefficient.

After the portion of the access platform is removed from the reactorwell or after the circular track arrangement is removed from the reactorpressure vessel, the reactor well and equipment storage area are floodedand the gate between the fuel storage pool and the reactor well isremoved to fill the reactor well with water for the refueling operation.The refueling operation now starts, which is transferring spent fuel tothe fuel storage area of the reactor fuel storage pool, and thereplenishing of the reactor with a new supply of fuel. To place thereactor back into operation, the reverse process is carried out.

SUMMARY OF THE INVENTION An elevator for a reactor well wherein aservice platform is moved in a vertical direction within the reactorwell and the vertically movable service platform is greater than thediameter of a reactor pressure vessel in the reactor well.

A feature of the present invention is the employment of telescopingtubes for moving the service platform vertically and the distancebetween movable tubes of the telescoping tubes is greater than thediameter of the reactor pressure vessel.

Another feature of the present invention is the provision of spacebetween the movable service platform and the adjacent superstructure ofthe refueling platform for the passage of tools and equipmenttherebetween.

Still another feature of the present invention is the ability to useboth sides of the service platform so that all functions other thanhandling fuel can be performed more efficiently.

By virtue of the present invention, an arrangement is provided wherebyworkers and the equipment employed by the workers can gain access to anylevel of the reactor well, to the equipment storage area and to anyposition above the reactor with facility, ease of operation, rapidly andsafely. Tools and equipment can be made available within the reactorwell. In some instances, by the greater expanse of the movable serviceplatform, access to auxiliary equipment is gained for moving a greaternumber of internal parts initially positioned within the reactor well.

DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of a reactor well andan equipment storage area employing the elevator of the presentinvention.

FIG. 2 is a diagrammatic view taken along line 2-2 of FIG. 1.

FIG. 3 is an enlarged perspective view of a reactor well and anequipment storage area employing the elevator of the present invention.

FIG. 4 is an enlarged fragmentary perspective view of the elevator ofthe present invention illustrated in conjunction with a reactor well anda fuel storage pool.

FIG. 5 is a fragmentary front elevation view of the elevator embodyingthe present invention illustrated in conjunction with a reactor well.

FIG. 6 is an enlarged end elevation view partially in section of theelevator embodying the present inventron.

FIG. 7 is an enlarged elevation view of telescoping tubes employed inthe elevator embodying the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Illustrated in FIGS. 1-3 is aconventional nuclear fuel storage pool P containing water and having atthe bottom thereof suitable facilities for storing nuclear fuel.Adjacent the fuel storage pool P is a conventional re'actor well W. Agate G separates thereactor well W and the storage pool P. When .thewater level in reactor well W is equal to that of storage pool P, gate Gis opened and water communicates between the storage pool P and reactorwell W.

Generally disposed within the reactor well W are a shielding block S, adrywell head D, a pressure vessel head H, a reactor pressure vessel V, asteam dryer SD, a steam separator SS, and a reactor core C (FIG. 2).

Refueling platforms for either a pressurized water reactor or a boilingwater reactor comprise a superstructure of steel with upright end frames11 and 12 interconnected by plates 15. The plates 15 are slightlygreater than the diameter of the reactor well W. Parallel tracks 19 and20 extend along side of the fuel storage pool P and the reactor well W.The end frames 11 and 12 of the superstructure 10 are supported bywheels 21 that travel along the tracks 19 and 20 for moving thesuperstructure 10 between the fuel storage pool P and the reactor wellW. In this manner, the reactor well W can be serviced for refueling andthe like and also fuel can be transported between the reactor well W andthe fuel storage pool P. The operation of the superstructure 10 alongthe tracks 19 and 20 is well-known in the art.

It is conventional to have an equipment storage area E at the oppositeside of the reactor well W from which the fuel storage pool is locatedfor storing the steam dryer and the steam separator as well as otherinternal equipment. Where there is an equipment storage area, then, ofcourse, the tracks 19 and 20 will extend a sufficient distance from thesuperstructure 10 to service the equipment storage area.

Fixed to the horizontal beams of the superstructure 10 are stationary,upright, tubes and 31 of steel. Of course, the stationary tubes 30 and31 will move with the refueling platform, but is fixedly positionedrelative to the superstructure l0. Telescopically received by the fixedtubes 30 and 31, respectively, are upright, movable tubes 32 and 33 ofsteel. Suitable bearings 34 and 35 (FIG. 7) are interposed respectivelybetween telescoping tubes 30-32 and 31-33 for maintaining stabilitybetween the telescoping tubes. The telescoping tubes30-32 and 31-33 arespaced apart a distance slightly greater than the diameter of thereactor pressure vessel V. More specifically, the distance between .theconfronting cylindrical walls of the movable tubes 32 and 33 is slightlygreater than the diameter of the reactor pressure vessel V. It isapparent that the movable tubes 32 and 33 may be in the form of rods orshafts.

Fixed to the movable tubes and, preferably, to the distal ends of themovable tubes 32 and 33 for vertical movement therewith is a serviceplatform 40. The service platform extends the entire distance betweenthe movable tubes 32 and 33. For raising and lowering the serviceplatform 40, a steel cable is received by the stationary tube 30 and isattached at its free end to the upper portion of the movable tube 32.The cable 50 is trained around pulleys 51 and 52. In addition, the cable50 is wound around a conventional drum 55. Similarly, a steel cable isreceived by the stationary tube 31 and is attached at its free end tothe upper portion of the movable tube 33. The cable 60 is trained aroundpulleys 61 and 62. In addtion, the cable 60 is wound around the drum 55.The drum 55 is electrically operated by means of an electrical systemwith a control box in a manner well known in the art. It is apparentthat a hydraulic system will operate equally as well.

Spacer 100 (FIG. 6) is provided between the sides of the serviceplatform 40 and the framework of the superstructure 10 to permit thefree passage of equipment grapple 101 therebetween. An auxiliary hoist70 is mounted from the superstructure l0 and is disposed outboard fromthe service elevator platform 40. An auxiliary pendant control 71 forcontrolling movement of the refueling platform along the rails and upand down movement of the service platform 40 is provided for the latterso that all the areas above the reactor core may be reached byhorizontal as well as vertical movement. At the beginning of a reactorshutdown, the normal control console 102 with its associated refuelinggrapple 103 is moved to the side and the refueling grapple is placed inits stored position which is out of the water. This enables the platform40 to travel from the refueling pool area to the reactor well and theequipment storage area. At this time, control is passed from therefueling platform to the service platform 40. This enables the serviceplatform 40 to travel in the horizontal direction and the verticaldirection in the reactor well and in the equipment storage area.

As will be further observed, a fixed walkway 45 for personnel isconnected between the superstructure uprights 11 and 12. The serviceplatform 40, as shown, is spaced from the walkway 45 to enable equipmentsuch as the grapple 101 to be extended down between the two. Both thewalkway 45 and platform 40 have personnel-containing railings 46 and 47,respectively, and the platform 40 as shows shown is to but has a shorterlength than that of the walkway 45.

I claim:

1. An elevator for a reactor well with a reactor pressure vessel in thereactor well comprising:

a. a superstructure extending across the reactor well and supported bysurfaces adjacent to the reactor well;

b. upright tubes supported by said superstructure and spaced apart adistance greater than the diameter of the reactor pressure vessel;

0. a movable upright member received by each of said upright tubes forvertical movement therein;

d. a platform carried by said movable upright members for verticalmovement therewith;

e. means supported by said superstructure and attached to said movableupright members for raising and lowering said movable upright members toimpart vertical movement to said platform, said mov able platform beinglaterally spaced from said superstructure; and

f. equipment mounted on the superstructure and extendible through thespace between the superstructure and movable platform.

2. An elevator as claimed in claim 1 wherein support means comprises acable for each of said movable tubes, each of said cables having thefree end portion thereof disposed within its associated tube supportedby said superstructure and attached to the upper portion of itsassociated movable tube, said cables being wound around drum means forraising and lowering the free ends thereof and being trained aroundpulleys for guiding the path of travel thereof.

3. An elevator as claimed in claim 1 wherein working access is providedon both sides of said movable platform.

4. Apparatus for providing access to equipment and parts in a nuclearreactor well sunk below a floor level and containing within the well areactor pressure vessel of given diameter, comprising a bridgesuperstructure having uprights supported on the floor level at oppositesides of the reactor well and upright connecting means extending overand across the reactor well, means for moving the bridge superstructurein a horizontal direction relative to the reactor well, an elongatedplatform for personnel having a length of approximately that of thediameter of the pressure vessel, means connected to the platform forsupporting same on the upright connecting means of the superstructure,means for moving the platform upward and downward relative to thesuperstructure and down into the reactor well to enable personnel on theplatform to have access to the reactor well and to the pressure vesseland parts contained therein, a walkway extending across the bridgesuperstructure, and means for laterally spacing the platform from thewalkway to enable equipment to be extended down between the platform andwalkway.

5. Apparatus as set forth in claim 4 and including rails on the floorlevel on opposite sides of the reactor well, said bridge superstructurebeing mounted on the rails for movement therealong.

6. Apparatus as set forth in claim 4 wherein the platform supportingmeans comprises plural supporting members connected to the platformsubstantially at opposite ends thereof.

7. Apparatus as set forth in claim 6 wherein the platform supportingmeans comprises a pair of telescoping tubes each having an upper endsecured to the bridge upight connecting means and a lower end secured toan end of the platform.

8. Apparatus for providing access to equipment and necting means of thesuperstructure, means for moving the platform upward and downwardrelative to the superstructure and down into the reactor well to enablepersonnel on the platform to have access to the reactor well and to thepressure vessel and parts contained therein, and a fixed walkwayextending across the bridge superstructure, said walkway extendinggenerally parallel to the platform and having a length longer than theplatform.

9. Apparatus as set forth in claim 8 and including protective railingson the walkway and platform.

1. An elevator for a reactor well with a reactor pressure vessel in the reactor well comprising: a. a superstructure extending across the reactor well and supported by surfaces adjacent to the reactor well; b. upright tubes supported by said superstructure and spaced apart a distance greater than the diameter of the reactor pressure vessel; c. a movable upright member received by each of said upright tubes for vertical movement therein; d. a platform carried by said movable upright members for vertical movement therewith; e. means supported by said superstructure and attached to said movable upright members for raising and lowering said movable upright members to impart vertical movement to said platform, said movable platform being laterally spaced from said superstructure; and f. equipment mounted on the superstructure and extendible through the space between the superstructure and movable platform.
 2. An elevator as claimed in claim 1 wherein support means comprises a cable for each of said movable tubes, each of said cables having the free end portion thereof disposed within its associated tube supported by said superstructure and attached to the upper portion of its associated movable tube, said cables being wound around drum means for raising and lowering the free ends thereof and being trained around pulleys for guiding the path of travel thereof.
 3. An elevator as claimed in claim 1 wherein working access is provided on both sides of said movable platform.
 4. Apparatus for providing access to equipment and parts in a nuclear reactor well sunk below a floor level and containing within the well a reactor pressure vessel of given diameter, comprising a bridge superstructure having uprights supported on the floor level at opposite sides of the reactor well and upright connecting means extending over and across the reactor well, means for moving the bridge superstructure in a horizontal direction relative to the reactor well, an elongated platform for personnel having a length of approximately that of the diameter of the pressure vessel, means connected to the platform for supporting same on the upright connecting means of the superstructure, means for moving the platform upward and downward relative to the superstructure and down into the reactor well to enable personnel on the platform to have access to the reactor well and to the pressure vessel and parts contained therein, a walkway extending across the bridge superstructure, and means for laterally spacing the platform from the walkway to enable equipment to be extended down between the platform and walkway.
 5. Apparatus as set forth in claim 4 and including rails on the floor level on opposite sides of the reactor well, said bridge superstructure being mounted on the rails for movement therealong.
 6. Apparatus as set forth in claim 4 wherein the platform supporting means comprises plural supporting members connected to the platform substantially at opposite ends thereof.
 7. Apparatus as set forth in claim 6 wherein the platform supporting means comprises a pair of telescoping tubes each having an upper end secured to the bridge upight connecting means and a lower end secured tO an end of the platform.
 8. Apparatus for providing access to equipment and parts in a nuclear reactor well sunk below a floor level and containing within the well a reactor pressure vessel of given diameter, comprising a bridge superstructure having uprights supported on the floor level at opposite sides of the reactor well and upright connecting means extending over and across the reactor well, means for moving the bridge superstructure in a horizontal direction relative to the reactor well, an elongated platform for personnel having a length of approximately that of the diameter of the pressure vessel, means connected to the platform for supporting same on the upright connecting means of the superstructure, means for moving the platform upward and downward relative to the superstructure and down into the reactor well to enable personnel on the platform to have access to the reactor well and to the pressure vessel and parts contained therein, and a fixed walkway extending across the bridge superstructure, said walkway extending generally parallel to the platform and having a length longer than the platform.
 9. Apparatus as set forth in claim 8 and including protective railings on the walkway and platform. 